There are some augers for sale on eBay, you might get lucky.
To get the rakes off the auger shaft of a couple of old Ariens machines, I had to slit them as shown,
and heat them in a 40 ton hydraulic press to get them off.
I covered the slit with epoxy and painted over it to keep water out, and you can barely tell. Painful at the time but I now have a spare auger assembly as a result: once I replace the seals...